Fastener



June 9 1931- H. RosENBERG FASTENER Filed July 25, 1926 H5. 57. 2f #wwwM55/V555@ PatentedV June 9, 1931 UNITED STATES PATENT lOFFICE FASTENERApplication filed July 23, 1926. Serial No. 124,454.

This invention relates toimprovements in fasteners of the typeespecially adapted for anchorage in metal and like substances, and,

more particularly to such as are formed of a body provided with a. ribor thread adapted to produce its own path in the work engaged. Amongvtheobjects in view are: first, to facilitate entry of the rib or thread torelatively great depth in the work with less resistance and strain thanmay be accomplished by the employment of the known forms of ribs orthreads; second, to form asmooth, finished path or thread in the workwith walls especially firmly gripping the rib or thread of the fastener;third, to increase the extent of purchase in engaging relatively thinsheet material by moving parts of such material to a flanged conditionin the direction of the length of the body of the fastener; and, fourth,to cause the fastener to readily and easily enter in a relativelystraight position with respect to the Work, that is, without canting orskewing.

Other objects will become in part apparent and in part be statedhereinafter;

The invention comprises certain novel constructions, combinations andarrangements of parts as hereinafter specified and claimed.

In the accompanying drawings,-

Figure 1 is a view in side velevation of a fastener embodying thefeatures of the present invention, the structure being shown in itsfully anchored position in Work, the working being seen in section.

Figure 2 is an end view of the fastener seen in Figure l, the workingbeing omitted.

Figure 3 is a side elevation similar to Figure l ofthe fa-stener takenfrom a plane at right angles to the plane of observation of Figure 1,the upper portion of the fastener being broken away and the work beingomitted.

Figures 4, 5, 6 and 7 are fragmentary, side elevations of the fastenershowing various stages of advance thereof into work.

Figure 8 is a view similar to Figure 3 of a slightly modifiedembodiment.

Figure 9 is a side elevation of the invention embodied in a lag screw,the parts being seen 5 on a reduced scale relative to the other figures.

0 Referring to the drawings by numerals, 1 indlcates the body or rootdiameter of a fastener having the head 2 provided with the 'usual kertOutstanding from the body l 1s a spiral rib or thread 4 of relativelyhigh pitch, that is, generally of the character of thread commonlyutilized on wood screws but differing therefrom in that the threadextends to the head 2, and differing therefrom also in the formation ofthe entering end portion of the thread,'as will hereinafter be describedin detail. The main portion of the rib or thread 4 outstands aconsiderable distance from the root diameterA or body 1 -so as to enterthe work engaged to a very substantial extent and thus afford especiallyeffective connection or anchorage. The rib or thread 4 is substantiallytriangular in transverse section with the apex presented outward or awayfrom the root diameter, so that an entering or cutting edge is presentedthroughout the length of the main portion of the rib or thread 4.

That portion of the rib or thread 4 extending beyond said main portionof the terminus of the body 1 will be referred to, for

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purposes of identification, as the entering end portion and tapersgradually, uniformily, and constantly longitudinally from the mainportion down to the eXtreme or terminus of the thread where it blendswith the root diameter or body 1. In addition to the said taper, thethread or rib 4 is formed with a groove or valley 5 extendingalong themedian line of the thread, the groove tapering inversely with the taperofthe thread from the beginning of the groove, as seen in Figure 3, tothe terminus thereof, as seen in Figure 1. The base of the groove orvalley 5 at the entering end is preferably inset radially inward of thelines of the root diameter or body l, and gradually rises until, as seenin Figure 3, it blends with the sides of the rib or thread to form thebeginning of the Y cutting edge of the main portion of thread or rib 4.The said sides of the rib formed by the groove or valley 5 eachterminate in an apex or cutting edge 4', which cutting edges extendalong and border the said groove or valley 5 throughout its length. Asclearly seen in Figures 1 and 3, the upper edge 4', that is, the edgenearer the head end of the fastener, is longer than the lower edge 4that is, the ed e nearer the entering end o the fastener. '`his greaterlength of the said upper edge 4' expresses itself in the form of anextension beyond the entering end of the lower edge 4 due to theinclination of the thread and the blending of both edges 4 into the rootdiameter on the same transverse plane of the root diameter, whereby asmooth or unthreaded ortion of the body or root diameter 1 is eft at theentering end providing a pilot 6 adapted to serve as a guide in locatingthe fastener at the beginning of an operation.

Since the improved fastener is designed and adapted especially for usein metallic work, and particularly relatively thin material, the thread4 throughout its length is preferably hardened to an extent suicient toenable the thread to enter or cut metal, such as soft iron or softsteel, substantially without injury to the thread. This hardening may beaccomplished by case-hardening the entire fastener Yas by the well knowncyaniding process, but it Shoud be borne in mind that the hardenedthread is the desired feature, and, therefore, such hardening as mayoccur to the root diameter or body 1 and to the head 2 is merelyincidental and not pre-requisite to the successful use of the fastener.Suilicient hardening of the head 2 and root diameter or body 1 forassuring adequate strength for the operation of the thread as hereindescribed is desirable, although, for most purposes, the materialemployed for the makin of the fasteners will have sufficient stabilitywithout such hardening, and i care should be exercised not toexcessively harden the body 1, as a degree of toughness is requiredsufficient to resist torsional strain and avoid crystallization undersuch strain.

The fastener is capable of use for many purposes and in variousmaterials, but is especlally well adapted for anchorage in metal, andthe metal work ma be possessed of a substantial body or may e of thethin sheet type, and, in either instance, an effective anchorage will beobtained by the use of the fastener.

In Figures 1 and 4 to 7 inclusive, a fastener is illustrated as engaginga sheet of metal 7 having a substantial body for purposes ofillustrating the functioning of the grooved or split thread. Thefastener, however, is well adapted for anchorage in sheets of metal ofany thickness. Fasteners embodying the invention are at presentextensively and successfully used for connecting sheet metal of eighteengauge to sheet metal of fourteen gauge after the manner of connectionindicated in Figure 1, the eighteen gauge sheet being the only sheetentered by the threads of the fastener. In said Figure 1 a sheet ofmaterial or work 9 is super-posed on a sheet 10, which in turn issuperposed on the sheet 7 and while thicknesses have been indicated asconsiderably exaggerated for purposes of ready disclosure, the method ofanchorage remains the same. It will, of course, be understood that thisillustrated use of a fastener is not to be accepted in a limiting senseas restricting the uses to which the fastener may be put. The fasteneris well adapted for use wherever anchorage is desired either to metal orother hard substances, such as hard rubber, bakelite, fiber-board, orthe like. The fastener, however, is especially adapted for use in metal.

It should be understood also that while the sheet 9 and sheet 10, whichlatter may be of felt, cardboard or the like, have been formed with anaperture .11 sufficiently large to permit the ready and free passage ofthe main portion of thread or rib 4, the said sheets may be formed withthe same character and size of opening as formed in sheet 7, or thefastener may be used for anchorage purposes directly to a mass or bodyof work Without the presence of other parts of work.

Whether the additional sheets or adjacent parts of work be employed ornot, with the form of anchorage device as seen in Figure 1, the work 7is formed preferably with a bore or hole of a size to readily receiveand to snugly t the pilot 6 which guides the entering movement of thescrew and keeps the screw at the proper angle to the work as the screwadvances.

When the pilot 6 has entered the aperture in the work suiiiciently forthe entering termini of the edges 4 to contact with the Work, thefastener or screw is revolved, as by the use of a screw-driver or likeinstrument engaging the kerf 3, and the said edges 4 enter the metal andform therein spaced grooves which are the beginnings of an internalthread. Owing to the location and form of the upper or longer edge 4,the entered material will be caused to iare upwardly, that is, in thedirection of the length of the fastener or screw toward thehead thereof,as clearly indicated in Figure 4. The continued rotation of the screw orfastener causes the entering ends of the edges 4 to pass on through thematerial of the work and beyond the same (when the work is of relativelthin sheet material), the said edges in passing through the lastportions of the material of the work causing said material to flare inthe direction of the length of the screw or fastener toward the pilot 6which has passed beyond the work, so that the material of the work hasthe effect of having been thickened about the fastener and an additionalpurchase for the fastener is thus provided. Continued rotation of thefastener or screw causes the material of the engaged work to flow tosuccessive positions, as indiloi lib

cated respectively in Figures 5, 6 and 7. As the thread or rib advancesthe bottom or base of the valley or groove 5 between the edges 4outstands more and more and begins to crowd the material of the worklying in the groove outward in a direction away fronrthe axis of thescrew. This outward crowding action is also accomplished by a pincheraction incident to the fact that the groove grows narrower as it growsless in depth, and the material of the work is thereby causedl to flowinto a more compact condition, which. compact condition is indicated bythe stippling at 12 in Figures 1, 5, 6 and 7. The material is thuscrowded and flowed outward to the very terminus of the split or groove 5inthe thread or rib 4, and thereafter is entered by thecutting edge ofthe main portion of said thread or rib 4, so that the material aboutsaid thread within the work isin close, firm contact with the thread andoffers powerful resistance to accidental dislocation. At the same time,it should be observed that because of the taper of the entering portionof thread 4, that is the portion provided with the groove 5, the saidentering portion finds its Way with relative ease and only acomparatively small amount of exerted energy to the final position forthe ready admission of the main portion of the thread or rib 4.

It is to be understood, of course, that the f fastener is adapted forall kinds of work as Well in material of unlimited thickness as thinsheet material and is capable of quite a'wide range of variations indetails, such as the proportions of the parts, the depth and length ofthe splitor groove 5, the length of the pilot 6, and other obviousfeatures. Also it will be noted that the screw may be provided With anentering point, as'seen at 13 in Figure 8, in which the parts, asidefrom the entering point, are identical with those above described andthe same reference numerals have been used and the same description willapply. The entering point 13 may Ahave any taper desired.

While the present invention is particularly designed for and especiallywell adapted to archorage in metallic work, it is also effec- Livelyuseful as a fastener in and for work of Wood, especially hard wood, andother fibrous and non-flowing materials, hard rubber, and the like. Ithas been found particularly Well adapted for use as a lag screw, as seenin Figure 9, in which the same reference numerals have been applied andthe same description Will apply, except that the head is designated as2, since the head of the screw` is squared to receive a rotatinginstrument. When the screw, as seen in Figure 9, is being used in Wood,hard rubber, or the like, the work is drilled or otherwise formed withan aperture proportioned to snugly receive the pilot of the screw. Thetapered point serves principally to center the screw quickly and easilyfor the entrance of the pi1ot,.and the thread takes hold immediatelyupon rotation of the screw. The advance of the screw, in-

cident to rotation, effects the formation of a 'thread in the materialengaged with vthe least possible tendency toward cracking or splittingthe material and a much more reliable and effective anchorage is thusaccomplished than may be secured by the use of the ordinary commerciallag screw. In utilizing the present invention no hammering of the screwis required as is customary with the ordinary lag screw.

Those embodiments disclosed herein and claimed generically but notspecifically because of the specific claiming in this case of the formof fastener whose body is of uniform and the same cross sectionthroughout its length, are reserved for specific claiming in myco-pending applications designated respectively Serial No. 277,607,filed May 14, 1928, and Serial No. 461,761, iiled June 17, 1930, thelatter as a continuation in part of Serial N o. 282,732` filed June 4,1928.

lVhat is claimed is I,

1. A fastener adapted for use yin metal Work comprising a body having arib outstanding along the body and grooved longitudinally, providing alongitudinally-extending exposed entering edge at one side of theygroove, the groove tapering along the rib.

2. A fastener adapted for use in metal Work comprising a bodyhaving arib outstanding along the body and grooved longitudinally, providinglongitudinally-extending exposed entering edges at the sides of thegroove, the groove tapering along the rib.

3. A fastener adapted for use in metal work comprising a body having arib outstanding along the body and grooved longitudinally, providing alongitudinally-extending exposed entering edge at one side of thegroove, the groove tapering along the rib and the groove extending tothe entering end of the rib.

4. A fastener adapted for use in metal work comprising a body having arib outstanding along the body and grooved longitudinally, providing alongitudinally-extending exposed entering edge at one side of thegroove, the groove tapering along the rib and the groove extending tothe entering end of therib, and the groove also having its maximum crosssectional area substantially at the entering end of the rib.

5. A fastener adapted for use in metal work comprising a. body having arib outstanding along the body and grooved longitudinally, providing alongitudinally-extending exposed entering edge at one side of thegroove, the groove tapering along the rib 'to exgiaustion short of thefull length of the r1 6. A fastener adapted for use in metal workcomprisin a body having a rib outstandin along t e body and groovedlongitudinal y, providing a longitudinally-extending exposed enteringedge at one side of the groove, the groove tapering along the rib toexhaustion short of the full length of the rib, and the rib tapering toexhaustion substantially at the entering end of the rib.

7. A fastener adapted for use in metal work comprising a body having arib outstanding along the body and formed with a tapering enteringportion, the rib having a groove along the median line of its taperingportion and correspondingly and inversely tapering and leaving anentering edge outstanding along one side of the groove.

8. A fastener adapted for use in metal work comprising a body having arib out-- standing along the body and formed with a tapering enteringportion, the rib having a groove along the median line of its taperingportion and correspondingly and inversely tapering from the entering endof the rib and leaving y outstanding entering edges along the groove,said edges terminating at the entering end of the rib in substantiallythe same transverse plane of the fas-tener at substantially right anglesto the longitudinal axis of the fastener.

9. A fastener adapted for use in metal Work comprising a body having athread outstanding along the body and grooved longitudinally, providinga longitudinallyextending exposed entering edge at one side 'of thegroove, the groove tapering along the thread. Y

10. A. fastener adapted for use in metal work comprising a body having arib out standing along the body and ooved longitudinally, providing alongitu inally-extending exposed entering edge at one side of thegroove, the groove taperin along the rib, and the body being ofsubstantially constant cross section throughout its length.

11. A fastener adapted for use in metal work comprising a body ofuniform and the same cross section throughout its length, and

yhaving a rib outstanding along the body and grooved longitudinally,providing a longitutudinally-extending exposed entering edge at one sldeof the groove, the groove tapering along the rib.

12. A fastener adapted for use in metal work comprising a body having athread spiraling about and along the body and grooved longitudinally,providing a longitudinallyextending exposed entering edge at one side ofthe groove, the groove tapering along the body, and the thread beingcontinuous and uninterru ted throughout its length.

13. A fastener or metal sheeting comprising a pin-like body and a threadoutstandtering ed e.

A astener for metal sheetin comprising a pin-like body of substantiayuni form cross section throughout its length including its entering endportion, and a thread outstanding from the body and having an outwardlypresented entering edge, said thread having a longitudinal grooveextending from the entering end of the thread along the thread andterminating short of the full length of the thread, and the thread beinghardened sufficiently for enterin metal, such as soft iron or softsteel, su stantially without injury to the thread, the ortions of thethread along the margins o the groove each having an outstandingentering edge, and the entering end of the thread being spaced from theentering end of the pinlike body for leaving a projecting pilot portion.

In testimon whereof I aiiix my signature.

{IEYMAN ROSENBERG.

